Lap counters and timing devices are widely used for training swimmers. The devices are unable to detect the effects of small changes in performance. Consequently, the effects of small changes in a swimmer's technique are overlooked. In competitive swimming, winners and losers are often decided by as little as a small fraction of an arm length. Small changes in a swimmer's performance can result in either a gold medal or a last place finish.
In my pending U.S. application Ser. No. 08/629,026, a training apparatus is disclosed which instantly informs a swimmer of the effects of changes in his form and/or movements on his performance. Not only is he able to instantly detect small changes in his performance, but also to improve his performance more quickly, because he can evaluate multiple changes in his technique during a single lap of a pool.
In the referenced pending application, a module is mounted on a swimmer and generates audio signals that vary in frequency with the swimmer's speed. The audio signals are transmitted to an earphone worn by the swimmer to permit him to evaluate whether his performance has improved.